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newbie-different question

hello all, if one would have told me that i would be here,even 2 days ago i wouldnt have believed them, but , here i am. i own a small auto diagnostic and

Message 1 of 2
, Jul 3, 2002

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hello all, if one would have told me that i would be here,even 2 days
ago i wouldnt have believed them, but , here i am. i own a small auto
diagnostic and general repair shop.recently i ebayed an accel digital
fuel injection "piggyback"controller that works by modifying certain
fuel and ignition points and is programmable "on the fly" via a
laptop computer and accels software called calmap-interface between
the 2 is via rs-232 cable and com1.well heres the rub-was having a
difficult time making contact -wasnt at all-with the box to start
calbrating it to my use. at some point i must of said to myself "new
approach required" and started browsing using rs232 as the keyword on
the net. soon i saw that txd and rxd were being used in the tutorials
i was reading-hey thats what the pin out schematic mentions
too,although later i would discover the pins were different because
of the age of my controller then typed in-tada-mc68hc11a1fn, not
knowing if this little chip within the processor had anything to do
with anything, but desperate i was.browsing several sites i noticed a
common thing- lookie there txd and rxd again.i was on to
something.started tracing the board and found the incorrect wiring
swapped them around and was communicating now, but with some errors
from time to time-echo mismatch and timeout error-but i was in
there.now the real drag-i built a test bench to work the programming
while stationary, to get a feel for the program-all was good till
yesterday and i shorted the board and sizzled a 5 volt supply wire
the laptop uses to verify connection is on(i think)re-soldered a new
little wire in its place 5 volts returned to where it belonged, but
now all i get is "timeout error" message when i try to hook up with
my computer now.did i fry my chip by doing the short circuit? isthere
a way to test this chip?/even if i buy a new one is it "blank" and
would need programming anyhow? i have burned eproms for cars but....
any input is appreciated and i will entertain all ideas put forth.
what a learning curve to end up this way.almost had it.oh-it appears
none of the barbecued circuit tracer hooked to the microcontroller,
however the symptoms say something is amiss. thanks for bearing with
me, frank

Scott Jantz

I am not sure what fried but replacement 68hc11a1s can be obtained from www.mrrobot.com and the other chip that can fry in that case is the RS-232 driver (5V

Message 2 of 2
, Jul 3, 2002

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I am not sure what fried but replacement 68hc11a1s can be obtained from www.mrrobot.com and the other chip that can fry in that case is the RS-232 driver (5V to +-12V converter). those chips can be obtained from the above site along with a board that will do the conversion from the a1s TX and RX lines to the laptop and that board is the MB2325.
Good luck,
--Scott
---------- Original Message ------------------- ---------------
From: "ctautorsto1" <ctautorsto1@...>
Reply-To: mrrobot@yahoogroups.com
Date: Wed, 03 Jul 2002 09:59:28 -0000

>hello all, if one would have told me that i would be here,even 2 days
>ago i wouldnt have believed them, but , here i am. i own a small auto
>diagnostic and general repair shop.recently i ebayed an accel digital
>fuel injection "piggyback"controller that works by modifying certain
>fuel and ignition points and is programmable "on the fly" via a
>laptop computer and accels software called calmap-interface between
>the 2 is via rs-232 cable and com1.well heres the rub-was having a
>difficult time making contact -wasnt at all-with the box to start
>calbrating it to my use. at some point i must of said to myself "new
>approach required" and started browsing using rs232 as the keyword on
>the net. soon i saw that txd and rxd were being used in the tutorials
>i was reading-hey thats what the pin out schematic mentions
>too,although later i would discover the pins were different because
>of the age of my controller then typed in-tada-mc68hc11a1fn, not
>knowing if this little chip within the processor had anything to do
>with anything, but desperate i was.browsing several sites i noticed a
>common thing- lookie there txd and rxd again.i was on to
>something.started tracing the board and found the incorrect wiring
>swapped them around and was communicating now, but with some errors
>from time to time-echo mismatch and timeout error-but i was in
>there.now the real drag-i built a test bench to work the programming
>while stationary, to get a feel for the program-all was good till
>yesterday and i shorted the board and sizzled a 5 volt supply wire
>the laptop uses to verify connection is on(i think)re-soldered a new
>little wire in its place 5 volts returned to where it belonged, but
>now all i get is "timeout error" message when i try to hook up with
>my computer now.did i fry my chip by doing the short circuit? isthere
>a way to test this chip?/even if i buy a new one is it "blank" and
>would need programming anyhow? i have burned eproms for cars but....
>any input is appreciated and i will entertain all ideas put forth.
>what a learning curve to end up this way.almost had it.oh-it appears
>none of the barbecued circuit tracer hooked to the microcontroller,
>however the symptoms say something is amiss. thanks for bearing with
>me, frank
>
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